INVESTIGADORES
JAHN Graciela Alma
congresos y reuniones científicas
Título:
Effect of 2,4-dichlorophenoxyacetic acid on dams exposed during lactation.
Autor/es:
POCCHETTINO A; JAHN GA; DUFFARD, R; EVANGELISTA A.
Lugar:
Mar del Plata
Reunión:
Congreso; LV Reunión Anual de la Sociedad Argentina de Investigación Clínica, Reunión Sociedad Argentina de Fisiologìa 2010 y XLII Reunión Sociedad Argentina de Farmacología Experimental; 2010
Institución organizadora:
Sociedad Argentina de Investigación Clínica
Resumen:
2,4-Dichlorophenoxyacetic acid (2,4-D) and its derivatives are herbicides widely used to control the growth of broadleaf and woody plants. Recently our laboratory has reported that 2,4-D exposed dams transfer the herbicide to suckling pups through mother’s milk. The goal of the present study was to evaluate the different stages of lactation in mother rats exposed to 2,4-D. Pregnant Wistar rats were treated with 2,4-D (70 mg/kg/day, sprayed on food) from gestation day 16 onward. On post partum day (PPD) the treated group continued to be fed with 2,4-D until sacrifice by decapitation at PPD 1, 7, 14 and 23. We determined serum prolactin (PRL), progesterone (P), insulin-like growth factor-1 (IGF-1), growth hormone (GH) and tyrosine hydroxylase (TH) inmunostaining in the arcuate nucleus (ArN). We observed a significant decrease in IGF-1 concentration at PPD 1 (52%), PPD 14 (56%) and PPD 23 (22%) respectively with respect to controls, but GH levels were not affected. The levels of PRL and P decreased significantly on day 7 (56% and 46%, respectively) and 14 (20% and 45%, respectively) of lactation There was increased TH inmunostaining in the ArN at PPD 7(9%), PPD 14 (11%) and PPD 23 (10%) with respect to controls. In conclusion, the increase of dopaminergic activity in ArN (estimated by increased TH - inmunostaining) produced by 2,4-D exposure may be the cause of the inhibition of PRL release, which in turn may be responsible for the decreased circulating P.